Astrophysical Bulletin最新文献

{"title":"Statistics of Coronal Mass Ejections in Solar Flares with Helioseismic Response","authors":"I. N. Sharykin,&nbsp;I. V. Zimovets","doi":"10.1134/S1990341324600856","DOIUrl":"10.1134/S1990341324600856","url":null,"abstract":"<p>This paper presents the results of a statistical analysis of the properties of coronal mass ejections (CMEs) associated with solar flares that exhibit a helioseismic response (‘‘sunquakes’’) in comparison with flares that do not show photospheric disturbances. The analysis is based on observations of the solar corona in the ultraviolet range (from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, SDO/AIA) and the visible range (from the Large Angle Spectroscopic Coronagraph on board the Solar and Heliospheric Observatory, SOHO/LASCO). We considered samples of flares with different lower thresholds based on the Geostationary Operational Environmental Satellites (GOES) classification: above M1.0, M5.0, and M7.0. A correlation analysis was also carried out between CME parameters and the total energy of the sunquakes. Additionally, for flares above M7.0-class, information on the presence of radio bursts across a wide range of wavelengths, as well as hard X-ray emission, was analyzed. It was found that CMEs accompanying flares with a helioseismic response tend to have higher velocities in the lower corona (according to AIA data) compared to flares without photospheric disturbances. The distribution of CME masses is approximately the same regardless of the presence or absence of sunquakes during the flares. An analysis of dimming properties showed that they are more impulsive in terms of temporal dynamics in flares with sunquakes. CMEs in flares above M7.0-class that exhibit helioseismic responses are less massive and slower in the outer corona according to LASCO data. The correlation analysis did not reveal strong relationships between acoustic energy and CME parameters based on AIA observations, but for several parameters (kinetic energy, CME mass, and dimming depth), statistically significant correlations were identified according to the <span>(t)</span>-criterion. In contrast to flares with sunquakes, there was an almost complete absence of type III radio bursts and a rare occurrence of type II bursts in the M7.0-class flares without photospheric disturbances. The spectral peak of microwave bursts tends to occur at higher frequencies in flares with sunquakes than in those without. According to our analysis, flares with sunquakes likely possess the ability to efficiently generate fast coronal dimmings and shock waves, even in the presence of poorly developed CMEs in the upper corona (in comparison to flares without photospheric disturbances). These events are also characterized by pronounced signatures of electron acceleration, with particles escaping the acceleration region both toward the solar surface and outward from it. In our view, this indicates that the possibility of an eruptive origin for sunquakes cannot be ruled out. Accelerated electrons may act as both the primary and secondary agents responsible for initiating the photospheric perturbation.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"294 - 311"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photometric Stability of an EMCCD Camera at 1-s Exposures","authors":"I. V. Afanasieva,&nbsp;V. G. Orlov,&nbsp;V. I. Ardilanov,&nbsp;V. A. Murzin,&nbsp;D. V. Oparin,&nbsp;A. N. Burenkov","doi":"10.1134/S1990341324600832","DOIUrl":"10.1134/S1990341324600832","url":null,"abstract":"<p>We present the results of testing an iXon Ultra 888 EMCCD camera to determine the operating parameters for short-exposure photometry of stars. As a result of the testing, those camera modes were selected in which the temporal instability of the electron multiplication charge does not significantly affect the light curves. In addition, the photometry of the eclipsing variable star ZTF J 0038+2030, obtained with the Zeiss-1000 telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences, is presented. We have shown the advantages and disadvantages of 1-s exposures for studying variable stars.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"312 - 320"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"W-DIMM: Test Measurements of Optical Turbulence Parameters at the Crimean Station of Sternberg Astronomical Institute","authors":"S. A. Potanin,&nbsp;A. Yu. Shikhovtsev,&nbsp;M. V. Kornilov,&nbsp;E. A. Kopylov,&nbsp;I. A. Gorbunov,&nbsp;A. V. Lyutyi,&nbsp;A. D. Savvin,&nbsp;M. E. Sachkov,&nbsp;M. V. Potanina","doi":"10.1134/S1990341324601023","DOIUrl":"10.1134/S1990341324601023","url":null,"abstract":"<p>A mobile W-DIMM device was used to measure seeing at the Crimean station of Sternberg Astronomical Institute of Moscow State University over seven nights, from June 23 to 30, 2024. Seeing estimates for altitudes greater than 500 m were inferred from scintillations in the sensor apertures separate from the total optical turbulence power. The zenith-adjusted seeing values were <span>(beta_{textrm{med}}approx 1overset{primeprime}{.}15)</span>, the corresponding seeing for the upper atmosphere was found to be of about <span>(0overset{primeprime}{.}28)</span>. A comparison of the seeing estimates obtained on these nights at telescopes with long exposures agrees well with the readings of the mobile differential image motion monitor. Some climatic parameters were also obtained both from a stationary weather station near the observation point and from satellite data.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"321 - 327"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activity of G Dwarf HD 284521 (K2-370) and Atmospheric Losses of Its Exoplanet","authors":"I. S. Savanov","doi":"10.1134/S1990341325600115","DOIUrl":"10.1134/S1990341325600115","url":null,"abstract":"<p>An analysis of the activity evidence of the chromospherically active solar-type dwarf HD 284521, which has a sub-Neptune-type planet, is presented. Based on the data from the Kepler and TESS missions, the stellar rotation period was estimated (<span>(P_{textrm{rot}}=13{-}14)</span> days) and the evolution of cold spots on its surface was examined. Estimates of the areas of these spots were obtained, which, according to the data from the Kepler mission, equaled about 3.2<span>(%)</span> and, according to TESS observations, about 2.3, 1.2, 2.3, and 2.5<span>(%)</span> of its surface area. Based on the data from the long-term Kamogata Wide-field Survey (KWS) and data from the All Sky Automated Survey (ASAS) observation archive, the value of the star’s long-term activity cycle was found to be about 3800 days (10.4 yrs). The cycle length is comparable to that of the Sun, but HD 284521 rotates about twice as fast as the Sun. An analysis of measurements of the <span>(S)</span> index characterizing the chromospheric activity of the star also indicates the presence of a long-period variability. The results obtained from studying the stellar activity were used to estimate the loss of atmospheric matter from the planet HD 284521 b. An approximation formula corresponding to the energy-constrained atmospheric loss model was applied. Based on 135 estimates of the <span>(S)</span> parameter, the matter loss from the atmosphere of HD 284521 b over an interval of 1886 days (approximately five years) was calculated. The matter losses (<span>(log M_{textrm{loss}})</span>) of the atmosphere of the planet HD 284521 b are in the range of 9.8 to 10.3 with a median value of 10.2. The high amount of matter loss from the atmosphere of this planet is due to a significant flux of XUV photons caused by the high activity of the solar-type star. The study of the planetary system HD 284521 continues our series of studies of planetary systems, in which the central star is an analog of the Sun.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"235 - 241"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studies of the Lagoon Nebula in the H({boldsymbol{alpha}}) Emission Line Using DEFPOS Spectrometer","authors":"M. Sahan","doi":"10.1134/S1990341324600480","DOIUrl":"10.1134/S1990341324600480","url":null,"abstract":"<p>DEFPOS Fabry–Perot spectrometer, located at the coude exit of the RTT-150 telescope (Bakirlitepe, Antalya, Turkey), has been used to measure the ionized gas within the Lagoon Nebula (M 8) which is an H II region (Sh2-25). Eighty-four H<span>(alpha)</span> emission line spectra obtained from the H II region provide detailed information about some physical properties of the gas surrounding the H II region. The line widths, <span>(V_{textrm{LSR}})</span> velocities, and <span>({I_{textrm{ H}{alpha}}})</span> intensities of the H<span>(alpha)</span> emission spectra were found to be in the range from <span>(27.5pm 5.80)</span> to <span>(41.50pm 1.99)</span> km s<span>({}^{-1})</span> (mean <span>(35.50pm 2.05)</span> km s<span>({}^{-1})</span>), <span>(-13.67pm 0.58)</span> and <span>(3.19pm 0.72)</span> km s<span>({}^{-1})</span> (mean <span>(-4.92pm 0.32)</span> km s<span>({}^{-1})</span>), and <span>(173.35pm 9.97)</span> R and <span>(13834.20pm 21.56)</span> R (mean <span>(2247.65pm 8.33)</span> R), respectively. The mean LSR velocity and line width of the nebula were also compared with previous works. Since there is not enough information on intensities and LSR velocities of such galactic sources with low angular size in the literature, we believe that DEFPOS spectrometer will provide a powerful tool for the study of the diffuse ionized gas, and these new results may have significant contributions to the literature.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"223 - 234"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three SU UMa Type Dwarf Novae in the Period Gap and Its Vicinity: CRTS J000130+050624, 1RXS J003828.7+250920 and V452 Cas","authors":"A. A. Sosnovskij,&nbsp;E. P. Pavlenko","doi":"10.1134/S1990341325600267","DOIUrl":"10.1134/S1990341325600267","url":null,"abstract":"<p>The results of photometric observations of three SU UMa type cataclysmic variables in the quiescent state (<span>(18overset{textrm{m}}{.}3-20overset{textrm{m}}{.}5)</span>) are presented. It is shown that the objects have different ouburst amplitudes: <span>(5^{textrm{ m}})</span>—CRTS J000130+050624; <span>(3overset{textrm{m}}{.}7)</span>—1RXS J003828.7+250920 and <span>(2overset{textrm{m}}{.}5)</span>—V452 Cas. The orbital period was first discovered for CRTS J000130+050624—0.09055(19) days, V452 Cas—0.084898(2) days, and updated for 1RXS J003828.7+250920—0.09451123(5) days. Ephemeris have been determined for the light curve minima of these objects associated with the orbital period. Estimates of the mass ratio of the components are <span>(q=0.181(6))</span>, <span>(0.198(1))</span>, <span>(0.183(2))</span> for 1RXS J003828.7+250920, CRTS J000130+050624, and V452 Cas, respectively. It is shown that these dwarf novae are located in the vicinity of the theoretical short-period boundary of the period gap and are in good agreement with known empirical data.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"173 - 180"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Age Estimation of the Radcliffe Wave from Open Star Clusters","authors":"V. V. Bobylev,&nbsp;N. R. Ikhsanov,&nbsp;A. T. Bajkova","doi":"10.1134/S1990341325600024","DOIUrl":"10.1134/S1990341325600024","url":null,"abstract":"<p>Four samples of open star clusters (OSCs) with average ages of 5.2, 18.6, 40, and 61 Myr have been analyzed. The selection of these OSCs was carried out from a narrow region inclined to the Galactic <span>(Y)</span> axis at an angle of <span>(25^{circ})</span>. Spectral analysis of the vertical positions and velocities of the selected clusters showed that the Radcliffe wave is associated with OSCs no older than 30 Myr. The following estimates of the Radcliffe wave characteristics were obtained for the OSCs with an average age of 5.2 Myr: <span>(z_{textrm{max}}=117pm 12)</span> pc with the wavelength <span>(lambda=4.55pm 0.14)</span> kpc, and the vertical velocity disturbance amplitude <span>(W_{textrm{max}}=4.86pm 0.19)</span> km s<span>({}^{-1})</span> with the wavelength <span>(lambda=1.74pm 0.08)</span> kpc. For the OSCs with an average age of 18.6 Myr, the estimates are as follows: <span>(z_{textrm{max}}=54pm 5)</span> pc and <span>(lambda=6.30pm 0.12)</span> kpc, and the vertical velocity disturbance amplitude <span>(W_{textrm{max}}=7.90pm 0.16)</span> km s<span>({}^{-1})</span> and <span>(lambda=0.83pm 0.11)</span> kpc. The radial motion of the Radcliffe wave away from the Galactic center has been confirmed. The velocity of such movement is 10 pc Myr<span>({}^{-1})</span>. In our opinion, the spatial distribution of OSCs younger than 30 Myr does not contradict the hypothesis of the association of the Radcliffe wave with the impact of shock waves from supernova explosions that arose on an extended front comparable in scale to the entire wave, that is, about 2 kpc in size.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"181 - 189"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Causes of Brightness Variability of a Young Star BP Tau","authors":"M. A. Burlak,&nbsp;K. N. Grankin,&nbsp;A. V. Dodin,&nbsp;A. V. Zharova,&nbsp;N. P. Ikonnikova,&nbsp;V. A. Kiryukhina,&nbsp;S. A. Lamzin,&nbsp;B. S. Safonov,&nbsp;I. A. Strakhov","doi":"10.1134/S1990341325600255","DOIUrl":"10.1134/S1990341325600255","url":null,"abstract":"<p>We have constructed and analyzed the secular light curve of BP Tau, a classical T Tau star. Wave-like variations in the average brightness level of the star with an amplitude of <span>(Delta Bapprox 0overset{textrm{m}}{.}2)</span> and a characteristic time of several decades were found. We present arguments in favor of the concept that three deep <span>((Delta Bsim 1overset{textrm{m}}{.}5))</span> dimming episodes lasting from one hour to several days are associated with the eclipse of a hot (accretion) spot by the dust infalling on the star along with gas. It is possible that such eclipses, albeit with a smaller amplitude, are the reason for the lack in BP Tau of a strictly expressed brightness variation periodicity related to axial rotation. We found that in the distance range of 0.1 to 200 AU, BP Tau has no companions with masses greater than <span>(0.2;M_{odot})</span>. Possible reasons of brightness and color index variability of the star on different time scales are discussed.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"279 - 293"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orbital Parameters, Radius and Classification of the Spectroscopic Binary Cepheid TX Del Based on Gaia DR3 Data","authors":"A. S. Rastorguev,&nbsp;M. V. Zabolotskikh,&nbsp;N. N. Samus,&nbsp;N. A. Gorynya","doi":"10.1134/S1990341325600103","DOIUrl":"10.1134/S1990341325600103","url":null,"abstract":"<p>A revision of the orbital parameters of the spectroscopic binary Cepheid TX Del, often classified as a BL Her subtype of T2 variables, has been carried out. The pulsation radius is determined from two series of photometric observations, including Gaia DR3: <span>(langle Rrangleapprox 22.4pm 0.8,R_{odot})</span> for the (<span>(B,V)</span>) bands and <span>(langle Rrangleapprox 20.6pm 0.6,R_{odot})</span> for the (<span>(BP,RP)</span>) bands, respectively. The amplitude of the radius variations is about <span>(2,R_{odot})</span>. The new radius estimates are significantly smaller than the previous estimates, which were in the range of 37 to 60 <span>(R_{odot})</span>. Using the Bayesian distance, <span>(langle Drangleapprox 1064pm 25)</span> pc, the absolute values of TX Del are estimated to be <span>(langle M_{V}rangle_{I}approx{-}1.31pm 0.04)</span> mag and <span>(langle M_{G}rangle_{I}approx{-}1.40pm 0.03)</span> mag, respectively. The absolute magnitude and mean radius of TX Del are in excellent agreement with the predictions of the ‘‘period–luminosity’’ and ‘‘period–radius’’ relations for T2 Cepheids with a period of <span>(P_{textrm{pls}}approx 6.1662)</span> days; TX Del is approximately <span>(2overset{textrm{m}}{.}2)</span> fainter than classical Cepheids with the same period. It is shown that for orbital plane inclination angles <span>(20^{circ}&lt;i&lt;(30{-}35)^{circ})</span> the satellite can be more massive than the main component, which leads to an evolutionary scenario with mass exchange. The current Roche sphere filling degree is <span>(37{-}55%)</span>. The orbit of the binary system TX Del calculated based on astrometric data from Gaia DR3 and radial velocity is limited by a <span>(|z|&lt;0.42)</span> kpc torus with the inner and outer radii equal to 7.2 and 8.3 kpc, respectively, while the vertical velocity is <span>(|V_{z}|leq 38)</span> km s<span>({}^{-1})</span>; the period of galactovertical oscillations is about 77 Myrs. The tangential velocity is 220–255 km s<span>({}^{-1})</span>. The high metallicity and kinematic characteristics allow us to refer TX Del to the population of the old disk of the Milky Way with a vertical scale <span>(H_{z}approx 0.3)</span> kpc (or to a thick disk with <span>(H_{z}approx 0.85)</span> kpc). At the same time, in terms of pulsation characteristics (period, luminosity, and position in the instability strip), TX Del is close to Population II Cepheids with <span>(textrm{[Fe/H]}&lt;{-}1)</span> (including globular cluster Cepheids) that are at the evolutionary stage after the horizontal branch. To finally clarify the evolutionary status of such variables, additional evolutionary and pulsation calculations are required over a wider range of periods and luminosities.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"242 - 253"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hercules Stream and the Outer Elliptical Ring (boldsymbol{R_{1}R_{2}})","authors":"A. M. Melnik,&nbsp;E. N. Podzolkova","doi":"10.1134/S1990341325600140","DOIUrl":"10.1134/S1990341325600140","url":null,"abstract":"<p>We study the formation of the Hercules stream in the model Galactic disk which includes the outer resonance ring <span>(R_{1}R_{2})</span> located near the Outer Lindblad Resonance (OLR) of the bar. The Hercules region and the anti-Hercules region, introduced for calibration, were restricted in space by the solar neighbourhood <span>(r&lt;0.5)</span> kpc, and on the (<span>(V_{R})</span>, <span>(V_{T})</span>) plane by ellipses centered at <span>(V_{R}=25)</span> km s<span>({}^{-1})</span> and <span>(V_{T}=200)</span> km s<span>({}^{-1})</span> (Hercules), and at <span>(V_{R}=-25)</span> km s<span>({}^{-1})</span> and <span>(V_{T}=200)</span> km s<span>({}^{-1})</span> (anti-Hercules). The number of stars in the Hercules region reaches a maximum in the time period of <span>(2-3)</span> Gyr from the start of simulation and the number of stars in the anti-Hercules region oscillates with a period of <span>(1.8pm 0.1)</span> Gyr. The majority of stars in the model disk located in the Hercules and anti-Hercules regions have orbits elongated perpendicular and parallel to the bar, respectively. The median value of the initial distances of stars in the Hercules (anti-Hercules) region is slightly smaller (larger) than the OLR radius, respectively. There are two types of orbits in the Hercules region. Orbits of the first type always lie inside a figure bounded by two ellipses elongated perpendicular to the bar. Orbits of the second type are elongated at the angles of <span>(-60^{circ})</span> or <span>(60^{circ})</span> to the major axis of the bar most of the time. The distribution of stars in the Hercules region along the period of slow oscillations in the angular momentum has two maxima: <span>(P=0.7)</span> and 2.6 Gyr corresponding to orbits of the first and second type. In the anti-Hercules region, most orbits are captured by libration relative to the major axis of the bar with a period of 1.9 Gyr. In general, orbits in the Hercules and anti-Hercules regions support the outer rings <span>(R_{1})</span> and <span>(R_{2})</span> elongated perpendicular and parallel to the bar, respectively. Stars from the Gaia DR3 catalog located in the Hercules region appear to be, on average, brighter, bluer, and more luminous than stars in the anti-Hercules region which is probably caused by selection effects due to different distributions of these stellar samples over the Galactic latitude <span>(b)</span>.</p>","PeriodicalId":478,"journal":{"name":"Astrophysical Bulletin","volume":"80 2","pages":"254 - 273"},"PeriodicalIF":1.4,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}